Housing-less plate heat exchangers are known that include a nested stack of heat exchange plates that define flow channels between the plates for the transfer of heat between first and second fluids flowing through the channels, with aligned openings in each of the plates defining inlet and outlet manifolds for the respective first and second fluids to distribute and collect the first and second fluids from the flow channels. Such heat exchangers are often used as oil coolers for vehicular engines or other machines. Typically, such heat exchangers include inlet ports and outlet ports located on the ends of the heat exchangers. However, some housing-less plate heat exchangers include inlet and outlet ports that emerge laterally from the heat exchanger. An example of such a construction is shown in International Patent Application WO 99/51926 wherein an inlet port and outlet port emerge laterally from an intermediate plate arranged between the nested stack of heat exchange plates. The disclosed heat exchanger is intended for heat exchange between three media and consists of two separate plate heat exchangers connected by the intermediate plate on which the lateral connections are arranged. The intermediate plate has a number of openings for the passage of various fluids, and its extent corresponds to the extent of the nested heat exchange plates and cover plates. The diameter of the connections for the inlet and outlet ports determines the thickness of the intermediate plate, so that a relatively thick intermediate plate is be present at large diameters.
An intermediate plate fitting for heat exchangers is also known from German patent document DE 31 02 314 C2, which does not however belong to the housing-less design. Rather, the construction is that of a coolant radiator that is provided with cooling fins for a cooling air stream flow. The construction does provide for inlet or outlet ports that emerge laterally from a plate type heat exchanger, but that require a two-part intermediate plate fittings to accommodate the corresponding intermediate plate fitting. These intermediate plates require that the adjacent heat exchange plates be modified so that they are configured differently then the other heat exchange plates in the construction. This can require an additional dye and an associated increase in terms of the logistic requirements associated with an increase in the number of different parts for the construction.